This invention relates to compositions which can be used to treat solid waste materials and the like, wastes such as soils, slurries and sludges which are contaminated with toxic metal pollutants and which must be safely discarded or rendered non-hazardous. Specifically, this invention relates to materials which can be used to treat soils and other solid wastes, sludges or slurries which are contaminated with toxic metals and where the toxic metals may be present as constituents in anionic, neutral, or cationic complexes such as chromium, chromate, dichromate, chromite, chromic, lead, plumbic, plumbous, plumbate, plumbite, arsenic, arsenate, arsenite, selenium, selenate, selenite, antimony, antimonite, antimonate, copper, cuprous, cupric, zinc, zincate, molybdenum, molybdic, molybdate, manganese, manganic, manganous, permanganate, vanadium, vanadic, and vanadate.
It is widely recognized that our industrial society produces solid wastes such as soils or sludges or slurries that are contaminated with various contaminants. In particular, toxic metals such as chromium are well known as soil pollutants or contaminants. For example, in areas where chromium ore has been processed, the soil associated therewith may become contaminated with chromium. This poses a health hazard to workers in the area as well as to the general public. It is desirable, therefore, to be able to treat this soil so that it can be disposed of safely without posing a threat to the public health or to the environment.
Other solid wastes, sludges and slurries that contain or are contaminated with chromium and/or other toxic metals are also known and these too must be disposed of safely. This is not always possible using prior art methods since the metals in the waste may still be mobile after treatment and thus are capable of being leached into ground-water.
Accordingly, it is an object of the invention to provide compositions which can be used to treat contaminated soils, sludges, slurries or other solid or semi-solid or semi-liquid wastes.
It is a further object of the invention to provide compositions that are particularly useful in treating soil or waste contaminated with toxic metals such as chromium and arsenic, where the metals may exist in or be capable of forming a higher oxidation state prior to or during treatment.
It is another object of the invention to provide compositions which can be used to treat toxic metals in soil or waste so that said soil or waste can be disposed of in an ecologically safe manner.
Still other objects and advantages of the invention will, in part, be obvious and will, in part, be apparent from the specification.